Multilayer material for color photography and method of making the same



0er. 29, 1940. B. GASPAR 12,219,987

MULTILAYER MATERIAL FOR COLOR PHOTOGRAPHY AND METHOD oF MAKING THE SAME Filed DeG. 3. 1938 mrs/WYE www xfa .seus/mf: an aux a om mso aow/fw: n'

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L i W//W//W//W/ WT 3 lwcntor QZQ/ khaar I Gtt'orncg Patented ct. 29, 1940 PATENT oFFlcE MULTILAYEB. MATERIAL FOR COLOR PHO- TOGRAPHY AND METHOD OF -MAKING 'riml sam:

"Bla Gaspar, Hollywood, Calif.

Application December 3, 1938, Serial No. 243,886 I In Great Britain December 9, 1937 z claims.

Multilayer light-sensitive materials are known in which at least one of the layers contains a dyestuff for forming the nal image, which dyestuif acts simultaneously as a screening dye for subsequent layers which might be sensitive to light to Which'the superposedlayer is to be exposed. The invention relates to materials of this kind and has for its object the provision of a material in which the amount and the distribution of the dyestuif is adapted to the desired screening effect on the one hand and to the requirements met with in the production of the multicolor image on the other hand. The invention is applicable in all cases in which the dyestuff quantity necessary for screen- I l5 ing a layer sensitive to the same light which is V used in the exposure of the preceding layer is in excess to that required in the most intensely colored parts of the nal image. l y i According to the inventiontwo'adjacent layers of light-sensitive emulsion are used, both of which contain the image-forming dyestuff. This means that one layer in a multilayer material or several or all of them are replaced by adouble layer one half of which contains the amount of dyestutf '25 necessary for the coloration of the most intensely colored parts of the image and the other half "layer of which contains 'such surplus of dyestuff as is required for preventing the light from penetrating into 'the layer which is to be'screened by the f='- dyestufvf. The'half of the layer which contains the surplus dyestuff is either sensitized for light rays which allow the individual and uniform exposureof this half or is fogged by a pre-treatment so that a uniform silver deposit will be obtained HP by developing. The layer maycalso contain exposed silver halide or colloidal silver which in the l'urther treatment acts to decolorize this half of the layer and thus reduces the dyestui concenvtration to the desired degree. 4u The position ofthe half of the layer intended to be decolorized and containing the"surplus dyestuff may be above or below with respect to the other half intended to yield the dyestuif image, or two layers to be decolorized and containing the 1 e 4.1 surplus dyestui may be arranged on both sides of the layer which yields the dyestuif image. If the dyestuif in the colored layer is to screen the layer itself, as for instance the yellow` image-forming vdyestuff in a three "layer material'containing a 50 blue sensitive front layer dyed magenta Iand a succeeding yellow dyed green sensitive layer, that half of the yellow layer'which contains the surc plus dyestulf faces the blue sensitive layer. In this case, this half of the yellow dyed emulsion i 65 may be sensitized to' infra-red light'and may be uniformly exposed-to suchl light.. If the third layer in the material is a blue sensitive layer which is to be exposed from the other side the yellow middle layer contains on both sides a yellow emulsion sensitizedlto infra-red. If on the 5 other hand the dyestuif in the colored layer is to screen the following layer, as for instance a yellow dyestuif in a blue-sensitive layer arranged inV front of one or more layers sensitized to green and red, but sensitive also to blue, that half ofthe yel- 10 low layer which contains the surplus dyestuff faces the following layers in the combined material. Thus, for example as shown in Fig. I of the drawing, the yellow dyed emulsion is applied in the form of two coatings on top of layers comprising a blue-green colored red-sensitive emulsion a'nd a superposed double layer of magenta coloredv green-sensitive emulsion. After the first coating of yellow emulsion has been applied the composite material may be subjectedto a weak 20 illumination by blue light sufficient to expose the yellow emulsion but not the other two. After that, a second coating of yellow emulsion may be applied, the dyestui concentration in this emulsion layer corresponding to the color intensity required at the most intensely colored parts of the image. The first` coating may be specially sensitized for infra-red as shown, in which case it may be uniformly exposed to such light as heretofore explained. In the same manner the'magenta 30 dyed emulsion may be produced by the application of two coatings.

Instead of applying the entire layer by separately coating two part layers, the wholelayer may be formed by a single coating process and there after different strata may be obtained .within this single layer by a surface illumination during'the manufacture of the layer or during the application thereof to the support. In order torender possible such exposure during the applica- 40 tion a special sensitization, for instance to infraredv light, is given to the layer or layers.

As shown in Fig. II of the drawing. a transparent support carries on the one side a yellowdyed silver halide emulsion Vlayer sensitized'to 45 green light, a yellow intermediate layer and a blue-sensitive magenta-colored layer on top` thereof. The other side of the support carries rst a yellow layer identical with the yellow intermediate layer cited above but-coated directly on the support. Upon this yellow layer there is coated on the outer lside a blue-sensitive emulsion of blue-green color.

The dyestulfs used are:

' For the yellow emulsion:

l0.6 g./sq.m. of Milling veloped or of an unexposed emulsion that, how- 7 Aever, contains cryptocyanine so that it may be uniformly exposed to infra-red light, or even of a colored gelatin solution of 21/2% in which 6 g/L colloidal silver are evenly distributed'.

The present invention A'is further'applicable in cases in which the colored colloid layer acting as a 4light-filter is used in combination with a silver halide emulsion layer not carrying the same dyestuff as the lter layer or a dyestuif of similar properties. Filter layers containing a dyestuif which is resistant to ordinary photographic treating solutions but capable of being bleached in the presence of metallic silver and further containing'means for uniformly decolorizing the layer under the influence of uniformly distributed silver, can be arranged in front of a light-sensitive layer which is colorless or colored and which may contain dyestuff-forming substances.

The means'for decolorizing may consist of colloidal silver,V of undeveloped silver halide which has been uniformly exposed or fogged or which can be uniformly illuminated owing to the presence of a sensitizer which renders the layer sensitive to light rays by which the layer can be illuminated without exposure of the differently sensitized layers. After the exposure of the material and after the production of latent images,

in the different layers and after the production of `the metailic silver? images `(the material having ,silver pictures -in the image-bearing layers and a uniform silver deposit in'the intermediate layer4 is treated with a Adye-destroying solution such as a 5 per cent hydrobromic acid or the solution of 3 per cent thiocarbamideand 1 per cent sulphuric acid which destroys the dyestuff in the filter layer 'in uniform manner. Thus, for example, as shown in Fig, III of the drawing, the front element of a bi-pack has a blue sensitive layervand a green sensitive layer coated on the sameside of a transparent support with the blue sensitive silver hali ide layer nextto the support and with the inter- The'rear film of the bi-pack carries an ordinary red-sensitive film. The bi-pack is exposed through the vsupport of the front element, developed and fixed. Thereafter, the front element is dyed by soaking it in a blue dyestuif solution, for example, a 1% solution of Pontamine Sky Blue which uniformly dyes all of the layers. The dyestuif is thereafter destroyed at the places of the silver deposit by treating with an acid thiocarbamidel solution or with hydrobromic acid, so that two blue colored images are obtained in the light-sensitive layers Whereas the dyestuff is destroyed totally inthe filter-layer. The remnant silver is bleached with a bleacher containing potassium bichromate for example one of the following formula: Potassium ferricyanide grams 37.5 Potassium bromide y do 56.25 -Potassium dichromate do 37.5 Acetic acid T ons" Water ccs-.. 2000 Potassium alum, 5 per cent solution ccs The vbleacher simultaneously acts to tan the gelatin. The film is xed with hypo and dried and thereafter treated with a 3 per cent sodium hydrosulphite solution which acts to decolorize the blue dyestuff image at the unhardened points of the upper layer but which is prevented from reaching `the second light-,sensitiveglayer byrthe uniformly hardened gelatin of the middle layer.y The decolorized outer layer still contains the tanned relief corresponding to the original silver image andthe unhardened places can,becolored by a water soluble dyestuif.

What is claimed is:

1. A light-sensitive multilayer material for color photographic purposes comprising several silver halide emulsion layers equa1 in number to the number of color selection pictures to be recorded in the material each being predominantly sensitized to a predetermined spectral range forv recording therein a color selection picture and an additional layer of colored colloid in front of one of said silver halide emulsion layers, said additional colloid layer being uniformly dyed with 4a dyestuff which is resistant to ordinary photographic treating solutions but capable of being bleached with the aid of metallic silver and which absorbs a spectral band for which said one of said silver halide emulsion layers is sensitive, but transmits light of `a different spectral region for i\which said one of said silver halide layers is predominantly sensitized, said additional colloid lay- )er further comprising an evenly distributed substance which is capable of assisting in the uniform bleaching of the dye by dye-destroying agents, said substance being selected from the group of substances which consists of finely distributed silver, colloidal silver, fogged silver halide emulsion, exposed silved halide and color sensitized silver halide sensitized `differently from the predominant sensitivities of said f rst mentioned silver halide emulsion layers.

2. A light-sensitive multilayer material for color photographic purposes comprising several silver halide emulsion layers equal in number to the number of color selection pictures to be recorded in the material each being predominantly sensi-V tized to a predetermined spectral range for. re,

cording therein a color selection picture at least one of the silver halide lemulsion layers being dyed with a` dye for the formationof the final image to the color intensity required at the most intensely colored parts of -the final image, the dye being resistant to ordinary photographic treating solutions but capable of being bleached with the aid of metallic silver, an additional colloid layer adjacent to the colored silver halide layer being uniformly dyed with substantially the same dyestui, the` additional colloid layer further comprising an evenly distributed ysubstance which is capable of assisting 'in the uniform bleaching of the dye by dye-destroying agents, said substance being selected from the group of substances, which consists of i'lnely distributed aul `color photography which comprises, forming a silver, colloidal silver, fogged silver halide emulsion, exposed silver halide and color sensitized silver halide sensitized differently from the predominant sensitivities of said rst mentioned sil- A ver halide emulsion layers.

3. A light-sensitive multilayer material for color photographic purposes comprising several sil- 4.

ver halide emulsion layers equal in number to the number of color selection pictures to be recorded in the material each being predominantly sensitized to a predetermined spectral range for recording therein a color selection picture, at least one of the silver halide emulsion layers being dyed with a dye for the formation of the final image to the color intensity required at the most `intensely colored parts of the final image, the

dye being resistant to ordinary photographic treating solutionsv but capable of being bleached with the aid of metallic silver, an additional col- 20 loid layer adjacent to each side of the colored silver halide layer being uniformly dyed with substantially the same dyestuff, the additional col- 4 'loid layers further comprising an evenly distributed substance which is capable of assisting in the uniform bleaching of the dye by dye-destroying agents, said substance being selected from the group of substances, which consists of finely -distributed silver, colloidal silver, fogged silver halide emulsion, exposed silver halide and color sensitized silver halide sensitized differently from the predominant sensitivities of said first mentioned silver halide emulsion layers.

4. A light-sensitive multilayer material for color photographic purposes comprising several silver halide emulsion layers equal in number to the lnumber of color selection pictures to be recorded in the material each being predominantly sensitized to a predetermined spectral range for recording therein a color selection picture, and an additional layer of colored colloid positioned between two of said sliver halide emulsion layers,

said additional colloidal layer being uniformlydyed vwith a dyestuif which is resistant to ordinary photographic treating solutions but capable of being bleached with the aid of metallic silver and which absorbs a spectral band for which one of said two silver halide emulsion layers is sensitive, but transmits light of a different spectral region for which said one of said two silver halide emulsion layers is predominantly sensitized, said additional colloidal layer further comprising an evenly distributed substance which is capable of assisting in the uniform bleaching of the dye by dye-destroying agents, said substance being selected from the group of substances which consists of finely distributed silver, colloidal silver, fogged silver halide emulsion, exposed silver halide and color sensitized silver halidelsensitized differently from the predominant sensitivities of 50 said first mentioned silver halide 4emulsion layers.

silver halide emulsion layer which is sensitive to a predetermined spectral range, coloring a silver halide emulsion which is sensitive to a range different from said predetermined spectral range and which is used for the production of the lter layer with a dye which is resistant to ordinary photographic treating solutions but capableofv emulsion layer is not sensitive to completely expose said filter layer and form therein a 'diffuse distribution of exposed silver halide.

6. A process of producing a colored filter layer in a multilayer photographic material for multicolor photography which comprises, forming a silver halide emulsion layer which is sensitive to a predetermined spectral range, coloring a silver halide emulsion which is sensitive to a range different from said predetermined spectral range and which is used for the production of the filter layer with a dye which is resistant to ordinary photographic treating solutions but capable of being bleached with the 'aid of metallic silver, forming a filter layerof said last mentioned emulsionwhich is superposed with respect to said rst mentioned emulsion layer, uniformly illuminating the said lter layer with light to which it is sensitive and to which said first mentioned emulsion'layer is not sensitive to completely expose said filter layer and form therein a diffuse distribution of exposed silver halide, and forming another superposed silver halide emulsion layer which is dyed with substantially the same dyeas said lter layer.

'7. A process of producing a colored filter layer in a multilayer photographic material for multicolor photography which comprises, coloring a silver halide emulsion which is sensitive to a predeterminedl spectral range, forming a layer of said emulsion, coloring a silver halide emulsion which is sensitive to a range different from said predetermined spectral -range and which is used kfor the production of the filter layer with a dye -mentioned emulsion layer is not sensitive to completely exposesaid filter layer and form therein a diffuse distribution of exposed silver halide.

BLA GASPAR. 

